Kinetic energy rod warhead with lower deployment angles

ABSTRACT

This invention features a kinetic energy rod warhead including a projectile core including a plurality of different size projectiles, an explosive charge about the core, and at least one detonator for the explosive charge.

RELATED APPLICATIONS

This application is a Continuation-in-Part application of U.S. patentapplication Ser. No. 10/456,777, filed Jun. 6, 2003 which is aContinuation-in-Part of U.S. patent application Ser. No. 09/938,022filed Aug. 23, 2001, issued on Jul. 29, 2003 as U.S. Pat. No. 6,598,534B2.

FIELD OF THE INVENTION

This invention relates to improvements in kinetic energy rod warheads.

BACKGROUND OF THE INVENTION

Destroying missiles, aircraft, re-entry vehicles and other targets fallsinto three primary classifications: “hit-to-kill” vehicles, blastfragmentation warheads, and kinetic energy rod warheads.

“Hit-to-kill” vehicles are typically launched into a position proximatea re-entry vehicle or other target via a missile such as the Patriot,THAAD or a standard Block IV missile. The kill vehicle is navigable anddesigned to strike the re-entry vehicle to render it inoperable.Countermeasures, however, can be used to avoid the “hit-to-kill”vehicle. Moreover, biological warfare bomblets and chemical warfaresubmunition payloads are carried by some threats and one or more ofthese bomblets or chemical submunition payloads can survive and causeheavy casualties even if the “hit-to-kill” vehicle accurately strikesthe target.

Blast fragmentation type warheads are designed to be carried by existingmissiles. Blast fragmentation type warheads, unlike “hit-to-kill”vehicles, are not navigable. Instead, when the missile carrier reaches aposition close to an enemy missile or other target, a pre-made band ofmetal on the warhead is detonated and the pieces of metal areaccelerated with high velocity and strike the target. The fragments,however, are not always effective at destroying the target and, again,biological bomblets and/or chemical submunition payloads survive andcause heavy casualties.

The textbook by the inventor hereof, R. Lloyd, “Conventional WarheadSystems Physics and Engineering Design,” Progress in Astronautics andAeronautics (AlAA) Book Series, Vol. 179, ISBN 1-56347-255-4, 1998,incorporated herein by this reference, provides additional detailsconcerning “hit-to-kill” vehicles and blast fragmentation type warheads.Chapter 5 of that textbook, proposes a kinetic energy rod warhead.

The two primary advantages of a kinetic energy rod warheads is that 1)it does not rely on precise navigation as is the case with “hit-to-kill”vehicles and 2) it provides better penetration then blast fragmentationtype warheads.

To date, however, kinetic energy rod warheads have not been widelyaccepted nor have they yet been deployed or fully designed. The primarycomponents associated with a theoretical kinetic energy rod warhead is ahull, a projectile core or bay in the hull including a number ofindividual lengthy cylindrical projectiles, and an explosive charge inthe hull about the projectile bay with sympthic explosive shields. Whenthe explosive charge is detonated, the projectiles are deployed.

The cylindrical shaped projectiles, however, may tend to break and/ortumble in their deployment. Still other projectiles may approach thetarget at such a high oblique angle that they do not effectivelypenetrate the target. See “Aligned Rod Lethality Enhanced Concept forKill Vehicles,” R. Lloyd “Aligned Rod Lethality Enhancement Concept ForKill Vehicles” 10^(th) AIAA/BMDD TECHNOLOGY CONF., Jul. 23-26,Williamsburg, Va., 2001 incorporated herein by this reference.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide an improvedkinetic energy rod warhead.

It is a further object of this invention to provide a higher lethalitykinetic energy rod warhead.

It is a further object of this invention to provide a kinetic energy rodwarhead with structure therein which aligns the projectiles when theyare deployed.

It is a further object of this invention to provide such a kineticenergy rod warhead which is capable of selectively directing theprojectiles at a target.

It is a further object of this invention to provide such a kineticenergy rod warhead which prevents the projectiles from breaking whenthey are deployed.

It is a further object of this invention to provide such a kineticenergy rod warhead which prevents the projectiles from tumbling whenthey are deployed.

It is a further object of this invention to provide such a kineticenergy rod warhead which insures the projectiles approach the target ata better penetration angle.

It is a further object of this invention to provide such a kineticenergy rod warhead which can be deployed as part of a missile or as partof a “hit-to-kill” vehicle.

It is a further object of this invention to provide such a kineticenergy rod warhead with projectile shapes which have a better chance ofpenetrating a target.

It is a further object of this invention to provide such a kineticenergy rod warhead with projectile shapes which can be packed moredensely.

It is a further object of this invention to provide such a kineticenergy rod warhead which has a better chance of destroying all of thebomblets and chemical submunition payloads of a target to thereby betterprevent casualties.

It is a further object of this invention to provide such a kineticenergy rod warhead which improves lethality against ballistic missileshaving submunition or bomblet payloads.

This invention results from the realization that a higher lethalitykinetic energy rod warhead which provides for high lethality ofballistic missiles having either submunition or bomblet payloads can beachieved by including a plurality of different size projectiles that areeffective against destroying both submunition and bomblet payloads.

This invention features a kinetic energy rod warhead including aprojectile core including a plurality of different size projectiles, anexplosive charge about the core, and at least one detonator for theexplosive charge.

In one embodiment, the plurality of different size projectiles mayinclude a larger number of small projectiles and a smaller number oflarge projectiles. The number of smaller projectiles may be chosen toincrease lethality against submunition payloads. The number of largerprojectiles may be chosen to increase lethality against bombletpayloads. The number of smaller projectiles may be chosen to increasethe spray pattern density of the projectiles. The number of largerprojectiles may be chosen to decrease the spray pattern density of theprojectiles. The smaller projectiles may be located proximate an outerregion of the core and the larger projectiles are located proximate thecenter region of the core. The plurality of different size projectilesmay include about seventy percent smaller projectiles and about thirtypercent larger projectiles. The mass of each large projectile may begreater than the mass of each of small projectile. All the projectilesmay have a cruciform cross section. The large and small projectiles maybe tightly packed in the core with minimal air spacing therebetween. Allthe projectiles may be made of tungsten. Each of the small projectilesmay weigh less than about 50 grams. Each of the small projectiles mayweigh approximately 28 grams. The projectiles may have a hexagon shape,a cylindrical cross section, a non-cylindrical cross section, a starshape cross section, flat ends, a non-flat nose, a pointed nose, or awedge-shape. The projectiles may be cube shaped or have athree-dimensional tetris shape.

This invention also features a kinetic energy rod warhead including aprojectile core including a large number of smaller projectiles and asmall number of larger projectiles, an explosive charge about the core,and at least one detonator for the explosive charge.

This invention further features a kinetic energy rod warhead including aprojectile core including a large number of smaller projectiles forincreasing the lethality against submunition payloads and a small numberof larger projectiles for increasing lethality against bomblet payloads,an explosive charge about the core, and at least one detonator for theexplosive charge.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages will occur to those skilled inthe art from the following description of a preferred embodiment and theaccompanying drawings, in which:

FIG. 1 is schematic view showing the typical deployment of a“hit-to-kill” vehicle in accordance with the prior art;

FIG. 2 is schematic view showing the typical deployment of a prior artblast fragmentation type warhead;

FIG. 3 is schematic view showing the deployment of a kinetic energy rodwarhead system incorporated with a “hit-to-kill” vehicle in accordancewith the subject invention;

FIG. 4 is schematic view showing the deployment of a kinetic energy rodwarhead as a replacement for a blast fragmentation type warhead inaccordance with the subject invention;

FIG. 5 is a more detailed view showing the deployment of the projectilesof a kinetic energy rod warhead at a target in accordance with thesubject invention;

FIG. 6 is three-dimensional partial cut-away view of one embodiment ofthe kinetic energy rod warhead system of the subject invention;

FIG. 7 is schematic cross-sectional view showing a tumbling projectilein accordance with prior kinetic energy rod warhead designs;

FIG. 8 is another schematic cross-sectional view showing how the use ofmultiple detonators aligns the projectiles to prevent tumbling thereofin accordance with the subject invention;

FIG. 9 is an exploded schematic three-dimensional view showing the useof a kinetic energy rod warhead core body used to align the projectilesin accordance with the subject invention;

FIGS. 10 and 11 are schematic cut-away views showing the use of fluxcompression generators used to align the projectiles of the kineticenergy rod warhead in accordance with the subject invention;

FIGS. 12-15 are schematic three-dimensional views showing how theprojectiles of the kinetic energy rod warhead of the subject inventionare aimed in a particular direction in accordance with the subjectinvention;

FIG. 16 is a three-dimensional schematic view showing another embodimentof the kinetic energy rod warhead of the subject invention;

FIGS. 17-23 are three-dimensional views showing different projectileshapes useful in the kinetic energy rod warhead of the subjectinvention;

FIG. 24 is an end view showing a number of star-shaped projectiles inaccordance with the subject invention and the higher packing densityachieved by the use thereof;

FIG. 25 is another schematic three-dimensional partially cut-away viewof another embodiment of the kinetic energy rod warhead system of thesubject invention wherein there are a number of projectile bays;

FIG. 26 is another three-dimensional schematic view showing anembodiment of the kinetic energy rod warhead system of this inventionwherein the explosive core is wedge shaped to provide a uniformprojectile spray pattern in accordance with the subject invention;

FIG. 27 is a cross sectional view showing a wedge shaped explosive coreand bays of projectiles adjacent it for the kinetic energy rod warheadsystem shown in FIG. 26;

FIG. 28 is a schematic depiction of a test version of a kinetic energyrod warhead in accordance with the subject invention with three separaterod bays;

FIG. 29 is a schematic depiction of the warhead of FIG. 28 after theexplosive charge sections are added;

FIG. 30 is a schematic depiction of the rod warhead shown in FIGS. 28and 29 after the addition of the top end plate;

FIG. 31 is a schematic view of the kinetic energy rod warhead of FIG. 30just before a test firing;

FIG. 32 is a schematic view showing the results of the impact of theindividual rods after the test firing of the warhead showing in FIG. 31;

FIG. 33 is a schematic view showing a variety of individual penetratorsrods after the test firing;

FIG. 34 is a schematic cross sectional view of a kinetic energy warheadwith lower deployment angles in accordance with this invention;

FIG. 35 is an exploded view showing the use of buffer disks between theindividual bays of projectiles in order to lower the deployment anglesof the rods in accordance with this invention;

FIG. 36 is a schematic depiction showing the use of a glass filleraround individual penetrators in order to lower the deployment angles inaccordance with this invention;

FIG. 37 is a schematic three-dimensional view showing a different typeof projectile in accordance with this invention including two frangibleportions;

FIG. 38 is a schematic three-dimensional view of a kinetic energy rodwarhead employing a plurality of different sized projectiles inaccordance with this invention;

FIG. 39 is a schematic cross-sectional view showing in further detailone example of the different sized projectiles shown in FIG. 38;

FIG. 40 is a schematic three-dimensional view showing that a largenumber of small projectiles is more effective against a ballisticmissile with a submunition payload;

FIG. 41 is a schematic three-dimensional view showing that a smallnumber of larger projectiles is more effective against a ballisticmissile with a bomblet payload;

FIGS. 42A-42C are schematic side views showing the packing density ofcruciform shaped projectiles and cylindrical rods in accordance withthis invention;

FIG. 43A is a schematic three-dimensional view of a cube shapedprojectile in accordance with this invention;

FIG. 43B is a schematic side view showing the packing density of thecube shaped projectile shown in FIG. 43A;

FIG. 44A is a three-dimensional view showing the tetris shapedprojectile in accordance with this invention; and

FIG. 44B is a schematic cross-sectional view showing the packing densityof the tetris shaped projectile shown in FIG. 44A.

DISCLOSURE OF THE PREFERRED EMBODIMENT

As discussed in the Background section above, “hit-to-kill” vehicles aretypically launched into a position proximate a re-entry vehicle 10, FIG.1 or other target via a missile 12. “Hit-to-kill” vehicle 14 isnavigable and designed to strike re-entry vehicle 10 to render itinoperable. Countermeasures, however, can be used to avoid the killvehicle. Vector 16 shows kill vehicle 14 missing re-entry vehicle 10.Moreover, biological bomblets and chemical submunition payloads 18 arecarried by some threats and one or more of these bomblets or chemicalsubmunition payloads 18 can survive, as shown at 20, and cause heavycasualties even if kill vehicle 14 does accurately strike target 10.

Turning to FIG. 2, blast fragmentation type warhead 32 is designed to becarried by missile 30. When the missile reaches a position close to anenemy re-entry vehicle (RV), missile, or other target 36, a pre-madeband of metal or fragments on the warhead is detonated and the pieces ofmetal 34 strike target 36. The fragments, however, are not alwayseffective at destroying the submunition target and, again, biologicalbomblets and/or chemical submunition payloads can survive and causeheavy casualties.

The textbook by the inventor hereof, R. Lloyd, “Conventional WarheadSystems Physics and Engineering Design,” Progress in Astronautics andAeronautics (AIAA) Book Series, Vol.179, ISBN 1-56347-255-4, 1998,incorporated herein by this reference, provides additional detailsconcerning “hit-to-kill” vehicles and blast fragmentation type warheads.Chapter 5 of that textbook, proposes a kinetic energy rod warhead.

In general, a kinetic energy rod warhead, in accordance with thisinvention, can be added to kill vehicle 14, FIG. 3 to deploy lengthycylindrical projectiles 40 directed at re-entry vehicle 10 or anothertarget. In addition, the prior art blast fragmentation type warheadshown in FIG. 2 can be replaced with or supplemented with a kineticenergy rod warhead 50, FIG. 4 to deploy projectiles 40 at target 36.

Two key advantages of kinetic energy rod warheads as theorized isthat 1) they do not rely on precise navigation as is the case with“hit-to-kill” vehicles and 2) they provide better penetration then blastfragmentation type warheads.

To date, however, kinetic energy rod warheads have not been widelyaccepted nor have they yet been deployed or fully designed. The primarycomponents associated with a theoretical kinetic energy rod warhead 60,FIG. 5 is hull 62, projectile core or bay 64 in hull 62 including anumber of individual lengthy cylindrical rod projectiles 66, sympethicshield 67, and explosive charge 68 in hull 62 about bay or core 64. Whenexplosive charge 66 is detonated, projectiles 66 are deployed as shownby vectors 70, 72, 74, and 76.

Note, however, that in FIG. 5 the projectile shown at 78 is notspecifically aimed or directed at re-entry vehicle 80. Note also thatthe cylindrical shaped projectiles may tend to break upon deployment asshown at 84. The projectiles may also tend to tumble in their deploymentas shown at 82. Still other projectiles approach target 80 at such ahigh oblique angle that they do not penetrate target 80 effectively asshown at 90.

In this invention, the kinetic energy rod warhead includes, inter alia,means for aligning the individual projectiles when the explosive chargeis detonated and deploys the projectiles to prevent them from tumblingand to insure the projectiles approach the target at a betterpenetration angle.

In one example, the means for aligning the individual projectilesinclude a plurality of detonators 100, FIG. 6 (typically chip slappertype detonators) spaced along the length of explosive charge 102 in hull104 of kinetic energy rod warhead 106. As shown in FIG. 6, projectilecore 108 includes many individual lengthy cylindrical projectiles 110and, in this example, explosive charge 102 surrounds projectile core108. By including detonators 100 spaced along the length of explosivecharge 102, sweeping shock waves are prevented at the interface betweenprojectile core 108 and explosive charge 102 which would otherwise causethe individual projectiles 110 to tumble.

As shown in FIG. 7, if only one detonator 116 is used to detonateexplosive 118, a sweeping shockwave is created which causes projectile120 to tumble. When this happens, projectile 120 can fracture, break orfail to penetrate a target which lowers the lethality of the kineticenergy rod warhead.

By using a plurality of detonators 100 spaced along the length ofexplosive charge 108, a sweeping shock wave is prevented and theindividual projectiles 100 do not tumble as shown at 122.

In another example, the means for aligning the individual projectilesincludes low density material (e.g., foam) body 140, FIG. 9 disposed incore 144 of kinetic energy rod warhead 146 which, again, includes hull148 and explosive charge 150. Body 140 includes orifices 152 thereinwhich receive projectiles 156 as shown. The foam matrix acts as a rigidsupport to hold all the rods together after initial deployment. Theexplosive accelerates the foam and rods toward the RV or other target.The foam body holds the rods stable for a short period of time keepingthe rods aligned. The rods stay aligned because the foam reduces theexplosive gases venting through the packaged rods.

In one embodiment, foam body 140, FIG. 9 maybe combined with themultiple detonator design of FIGS. 6 and 8 for improved projectilealignment.

In still another example, the means for aligning the individualprojectiles to prevent tumbling thereof includes flux compressiongenerators 160 and 162, FIG. 10, one on each end of projectile core 164each of which generate a magnetic alignment field to align theprojectiles. Each flux compression generator includes magnetic coreelement 166 as shown for flux compression generator 160, a number ofcoils 168 about core element 166, and explosive charge 170 whichimplodes magnetic core element when explosive charge 170 is detonated.The specific design of flux compression generators is known to thoseskilled in the art and therefore no further details need be providedhere.

As shown in FIG. 11, kinetic energy rod warhead 180 includes fluxcompression generators 160 and 162 which generate the alignment fieldsshown at 182 and 184 and also multiple detonators 186 along the lengthof explosive charge 190 which generate a flat shock wave front as shownat 192 to align the projectiles at 194. As stated above, foam body 140may also be included in this embodiment to assist with projectilealignment.

In FIG. 12, kinetic energy rod warhead 200 includes an explosive chargedivided into a number of sections 202, 204, 206, and 208. Shields suchas shield 225 separates explosive charge sections 204 and 206. Shield225 maybe made of a composite material such as a steel core sandwichedbetween inner and outer lexan layers to prevent the detonation of oneexplosive charge section from detonating the other explosive chargesections. Detonation cord resides between hull sections 210, 212, and214 each having a jettison explosive pack 220, 224, and 226. Highdensity tungsten rods 216 reside in the core or bay of warhead 200 asshown. To aim all of the rods 216 in a specific direction and thereforeavoid the situation shown at 78 in FIG. 5, the detonation cord on eachside of hull sections 210, 212, and 214 is initiated as are jettisonexplosive packs 220, 222, and 224 as shown in FIGS. 13-14 to eject hullsections 210, 212, and 214 away from the intended travel direction ofprojectiles 216. Explosive charge section 202, FIG. 14 is then detonatedas shown in FIG. 15 using a number of detonators as discussed withreference to FIGS. 6 and 8 to deploy projectiles 216 in the direction ofthe target as shown in FIG. 15. Thus, by selectively detonating one ormore explosive charge sections, the projectiles are specifically aimedat the target in addition to being aligned using the aligning structuresshown and discussed with reference to FIGS. 6 and 8 and/or FIG. 9 and/orFIG. 10.

In addition, the structure shown in FIGS. 12-15 assists in controllingthe spread pattern of the projectiles. In one example, the kineticenergy rod warhead of this invention employs all of the alignmenttechniques shown in FIGS. 6 and 8-10 in addition to the aimingtechniques shown in FIGS. 12-15.

Typically, the hull portion referred to in FIGS. 6-9 and 12-15 is eitherthe skin of a missile (see FIG. 4) or a portion added to a “hit-to-kill”vehicle (see FIG. 3). Further details of the frangible skin employed inthe kinetic energy rod warhead of this invention are discussed in detailbelow.

Thus far, the explosive charge is shown disposed about the outside ofthe projectile or rod core. In another example, however, explosivecharge 230, FIG. 16 is disposed inside rod core 232 within hull 234.Further included may be low density material (e.g., foam) buffermaterial 236 between core 232 and explosive charge 230 to preventbreakage of the projectile rods when explosive charge 230 is detonated.

Thus far, the rods and projectiles disclosed herein have been shown aslengthy cylindrical members made of tungsten, for example, and havingopposing flat ends. In another example, however, the rods have anon-cylindrical cross section and non-flat noses. As shown in FIGS.17-24, these different rod shapes provide higher strength, less weight,and increased packaging efficiency. They also decrease the chance of aricochet off a target to increase target penetration especially whenused in conjunction with the alignment and aiming methods discussedabove.

Typically, the preferred projectiles do not have a cylindrical crosssection and instead may have a star-shaped cross section, a cruciformcross section, or the like. Also, the projectiles may have a pointednose or at least a non-flat nose such as a wedge-shaped nose. Projectile240, FIG. 17 has a pointed nose while projectile 242, FIG. 18 has astar-shaped nose. Other projectile shapes are shown at 244, FIG. 19 (astar-shaped pointed nose); projectile 246, FIG. 20; projectile 248, FIG.21; and projectile 250, FIG. 22. Projectiles 252, FIG. 23 have astar-shaped cross section, pointed noses, and flat distal ends. Theincreased packaging efficiency of these specially shaped projectiles isshown in FIG. 24 where sixteen star-shaped projectiles can be packagedin the same space previously occupied by nine penetrators or projectileswith a cylindrical shape.

Thus far, it is assumed there is only one set of projectiles. In anotherexample, however, the projectile core is divided into a plurality ofbays 300 and 302, FIG. 25. Again, this embodiment may be combined withthe embodiments shown in FIGS. 6 and 8-24. In FIGS. 26 and 27, there areeight projectile bays 310-324 and cone shaped explosive core 328 whichdeploys the rods of all the bays at different velocities to provide auniform spray pattern. Also shown in FIG. 26 is wedged shaped explosivecharge sections 330 with narrower proximal surface 334 abuttingprojectile core 332 and broader distal surface 336 abutting the hull ofthe kinetic energy rod warhead. Distal surface 336 is tapered as shownat 338 and 340 to reduce the weight of the kinetic energy rod warhead.

In one test example, the projectile core included three bays 400, 402and 404, FIG. 28 of hexagon shaped tungsten projectiles 406. The otherprojectile shapes shown in FIGS. 17-24 may also be used. Each bay washeld together by fiberglass wrap 408 as shown for bay 400. The bays 400,402 and 404 rest on steel end plate 410. Buffer 407 is inserted aroundthe rod core. This buffer reduces the explosive edge effects actingagainst the outer rods. By mitigating the energy acting on the edge rodsit will reduce the spray angle from the explosive shock waves.

Next, explosive charge sections 412, 414, 416 and 418, FIG. 29 weredisposed on end plate 410 about the projectile core. Thus, the primaryfiring direction of the projectiles in this test example was alongvector 420. Clay sections 422, 424, 426 and 428 simulated the additionalexplosive sections that would be used in a deployed warhead. Betweeneach explosive charge section is sympathetic shield 430 typicallycomprising steel layer 432 sandwiched between layers of Lexan 434 and436. Each explosive charge section is wedge shaped as shown withproximal surface 440 of explosive charge section 412 abutting theprojectile core and distal surface 442 which is tapered as shown at 444and 446 to reduce weight.

Top end plate 431, FIG. 30 completes the assembly. End plates 410 and431 could also be made of aluminum. The total weight of the projectilerods 406 was 65 pounds, the weight of the C4 explosive charge sections412, 414, 416, and 418 was 10 pounds. Each rod weighed 35 grams and hada length to diameter ratio of 4. 271 rods were packaged in each bay with823 rods total. The total weight of the assembly was 30.118 pounds.

FIG. 31 shows the addition of detonators as shown at 450 just beforetest firing. There was one detonator per explosive charge section andall the detonators were fired simultaneously. FIG. 32-33 shows theresults after test firing. The individual projectiles struck testsurface 452 as shown in FIG. 32 and the condition of certain recoveredprojectiles is shown in FIG. 33.

To reduce the deployment angles of the projectiles when the detonatorsdetonate the explosive charge sections thereby providing a tighter spraypattern useful for higher lethality in certain cases, several additionalstructures were added in the modified warhead of FIG. 34.

One means for reducing the deployment angles of projectiles 406 is theaddition of buffer 500 between the explosive charge sections and thecore. Buffer 500 is preferably a thin layer of poly foam {fraction(1/2)} inch thick which also preferably extends beyond the core toplates 430 and 412. Buffer 500 reduces the edge effects of the explosiveshock waves during deployment so that no individual rod experiences anyedge effects.

Another means for reducing the deployment angles of the rods is theaddition of poly foam buffer disks 510 also shown in FIG. 35. The disksare typically {fraction (1/8)} inch thick and are placed between eachend plate and the core and between each core bay as shown to reduce slapor shock interactions in the rod core.

Momentum traps 520 and 522 are preferably a thin layer of glass appliedto the outer surface of each end plate 410 and 430. Also, thin aluminumabsorbing layers 530 and 532 between each end plate and the core help toabsorb edge effects and thus constitute a further means for tighteningthe spray pattern of the rods.

In some examples, selected rods 406 a, 406 b, 406 c, and 406 d extendcontinuously through all the bays to help focus the remaining rods andto reduce the angle of deployment of all the rods. Another idea is toadd an encapsulant 540, which fills the voids between the rods 406, FIG.36. The encapsulant may be glass and/or grease coating each rod.Preferably, there are a plurality of spaced detonators 450 a, 450 b, and450 c, FIG. 32 for each explosive charge section each detonatortypically aligned with a bay 400, 402, and 404, respectively, to providea flatter explosive front and to further reduce the deployment angles ofrods 406. Another initiation technique could be used to reduce edgeeffects by generating a softer push against the rods. This concept wouldutilize backward initiation where the multiple detonators 450 a′, 450b′, and 450 c′ are moved from their traditional location on the outerexplosive to the inner base proximate buffer 500. The explosiveinitiators are inserted at the explosive/foam interface which generatesa flat shock wave traveling away from the rod core. This initiationlogic generates a softer push against the rod core reducing all lateraledge effects.

Another idea is to use rod 406 e, FIG. 37 at select locations or evenfor all the rods. Rod 406 e extends through all the bays but includesfrangible portions of reduced diameter 560 and 562 at the intersectionof the bays, which break upon deployment dividing rod 406 e into threeseparate portions 564, 566, and 568.

The result with all, a select few, or even just one of these exemplarystructural means for reducing the deployment angles of the rods orprojectiles when the detonator(s) detonate the explosive charge sectionsis a tighter, more focused rod spray pattern. Also, the means foraligning the projectiles discussed above with reference to FIGS. 6-11and/or the means for aiming the projectiles discussed above withreference to FIGS. 12-15 may be incorporated with the warheadconfiguration shown in FIGS. 34-35 in accordance with this invention.

In one preferred embodiment, the kinetic energy rod warhead of thisinvention includes a plurality of different size projectiles which areeffective against ballistic missiles having submunition or bombletpayloads. The different size projectiles typically include a largenumber of small projectiles which are effective against destroyingsubmunition payloads and a small number of larger, typically heavierprojectiles which are effective against destroying bomblet payloads.

For example, kinetic energy rod warhead 600, FIG. 38, includesprojectile core 602 including plurality 604 of different sizeprojectiles. The projectiles ideally include a larger number of smallprojectiles 606 and a smaller number of large projectiles 608. The largeprojectiles are typically heavier than the small projectiles, typicallyweighing about 113.7 g compared to about 28.6 g for the smallprojectiles. Warhead 600 also includes an explosive charge divided intoa number of sections 610, 612, 614, 616, 618, 620, 622 and 624. Shields,such as shield 626, separate explosive charge sections 610 and 612.Warhead 600 also includes a plurality of detonators, such as detonators628, 630, 632, 634, 636, 638, 640 and 642. Selected detonators 628-640(typically chip slapper-type detonators) are used to initiate selectedexplosive charge sections 610-624 and deploy the plurality of differentsize projectiles. Foam body 603, similar to foam body 140, FIG. 9, asdiscussed above, may be employed to surround core 602, FIG. 38, forimproved projectile alignment. The smaller projectiles 606 are effectiveat destroying ballistic missiles having submunition payload and thelarger, heavier projectiles 608 are effective at destroying bombletpayloads. The result is that kinetic energy rod warhead 600 of thisinvention effectively destroys ballistic missiles having eithersubmunition or bomblet payloads, as discussed in further detail below.

FIG. 39, where like parts have been given like numbers, shows anenlarged view of projectile core 602 including smaller projectiles 606and larger projectiles 608. In this example, all the projectiles have acruciform cross section. The projectiles may also include cube shapedprojectiles, such as cube shaped projectiles 652 and tetris shapedprojectiles, such as tetris shaped projectiles 654.

Typically, smaller projectiles 606 are located proximate outer region802 of core 602 while the larger projectiles 608 are located proximatethe center region 804 of core 602.

In one design, the projectiles include about 70% smaller projectiles 606and about 30% larger projectiles 608. The mass of each of the largeprojectiles 608 is typically greater than the mass of each of the smallprojectiles 606. In one example, the mass of each small projectiles 606in core 602 is about 28 grams and the mass of each of the largeprojectiles 608 is about 114 grams. The plurality of different sizeprojectiles may be made of tungsten or similar materials.

A simulation showing that a larger number of smaller projectiles is moreeffective against a ballistic missile having a submunition payload isshown in FIG. 40. In this example, the smaller projectiles, e.g., 128projectiles, indicated at 758, are effective at destroying submunitionpayloads, as shown by the destroyed submunitions indicated at 760. Incontrast, when a fewer number of projectiles were deployed, e.g., 32projectiles, as indicated at 762, fewer submunitions were destroyed, asshown by the destroyed submunitions indicated at 764. When four largeprojectiles were deployed, as indicated at 766, only three submunitionswere destroyed, as indicated at 768. A large number of smallerprojectiles or rods is also shown at 770 impacting submunition payload772. As shown at 774, the large number of small projectiles or rodscreated substantial damage to the submunition payload 772. In contrast,when a small number of large projectiles indicated at 776 were deployedagainst submunition payload 772, only minimal damage resulted tosubmunition payload 772, as indicated at 778.

FIG. 41 is a simulation showing that a few larger, heavier projectilesare very effective against ballistic missiles having bomblet payloads.In this example, when a small number of larger projectiles, e.g., fourheavier projectiles or rods each weighing about 2273 grams, as indicatedat 780 are deployed the large projectiles penetrated bomblet payload 782and destroyed almost all the bomblets therein, as indicated by destroyedbomblets 784. However, when a larger number of rods were used, e.g., 128rods each weighing about 276 grams, as indicated at 784, the largernumber of smaller projectiles or rods did not destroy the aft bomblets,as indicated by live bomblets 788. When an even larger number of smallerprojectiles or rods where deployed, e.g., 1024 rods each weighing about31 grams, as indicated at 790 a substantial portion of the aft bombletswere not destroyed, as shown by the live bomblets 792. Hence, a smallnumber of larger and heavier penetrators are more effective atdestroying ballistic missiles having bomblet payloads.

Because kinetic energy rod warhead 600, FIG. 38 of this inventiondeploys both a large number of small projectiles and a small number oflarger and heavier projectiles or rods at the same time, warhead 600effectively destroys ballistic missiles having submunition and/orbomblet payloads.

As discussed above, the different size rods ideally have a cruciformcross section. The cruciform shaped rods provide for tight packing ofthe projectiles within core 602 with minimal air space therebetween.Tight packing of the cruciform cross-sectional shaped projectilesprovides for a larger number of projectiles to be packed within core 602than cylindrical shaped rods. For example, as shown in FIG. 42A thepacking density of the cruciform shaped rods 660 allows about 80projectiles to be packed projectile core 602. In contrast, cylindricalshaped rods 662 FIG. 42B allows only about 56 rods or projectiles to bepacked in core 602. The cruciform shaped rods can be even more tightlypacked, as shown in FIG. 42C, where, in this example, 113 cruciformprojectiles 662 were packed within the core 602. The higher number ofprojectiles that can be packed within core 602 provide a higher spraypattern density on the enemy target. In this example, the largercruciform shaped rods 660 have a diameter of about 0.75 inches and eachweigh about 34.4 grams and cruciform shaped rods 662 have a diameter ofabout 0.375 inches and each weigh about 25.2 grams. Moreover, the use ofcruciform projectiles or penetrators are effective against bulk orliquid filled tanks because they enhance the transfer of kinetic energycausing hydraulic ram effects. This process is caused by high shockpressure with projectile drag causing sub-explosive forces on the tankwall.

As discussed above, the preferred projectiles do not have a cylindricalcross-section and instead have cruciform cross-section. Also, theprojectiles may have a pointed nose or at least a non-flat nose such asa wedge-shaped nose. Projectile 240, FIG. 17 has a pointed nose whileprojectile 242, FIG. 18 has a star-shaped nose. Other projectile shapesare shown at 244, FIG. 19 (a star-shaped pointed nose); projectile 246,FIG. 20; projectile 248, FIG. 21; and projectile 250, FIG. 22.Projectiles 252, FIG. 23 have a star-shaped cross section, pointednoses, and flat distal ends. The increased packaging efficiency of thesespecially shaped projectiles is shown in FIG. 24 where sixteenstar-shaped projectiles can be packaged in the same space previouslyoccupied by nine penetrators or projectiles with a cylindrical shape.The projectiles or rods may also be cube shaped, as shown in FIG. 43A.The cube shape also provides for a tightly packed density, as shown inFIG. 43B. Typically each cube has a mass of about 50 grams and about 48cubes may be packed in core 602. The plurality of projectiles may have athree-dimensional tetris shape as shown in FIG. 44A. The tetris shapedrods also provide for a tightly packed density in core 602, as shown inFIG. 44B.

Although specific features of the invention are shown in some drawingsand not in others, this is for convenience only as each feature may becombined with any or all of the other features in accordance with theinvention. The words “including”, “comprising”, “having”, and “with” asused herein are to be interpreted broadly and comprehensively and arenot limited to any physical interconnection. Moreover, any embodimentsdisclosed in the subject application are not to be taken as the onlypossible embodiments.

Other embodiments will occur to those skilled in the art and are withinthe following claims:

1. A kinetic energy rod warhead comprising: a projectile core includinga plurality of different size projectiles; an explosive charge about thecore; and at least one detonator for the explosive charge.
 2. Thekinetic energy rod warhead of claim 1 in which the plurality ofdifferent size projectiles includes a larger number of small projectilesand a smaller number of large projectiles.
 3. The kinetic energy rodwarhead of claim 2 in which the number of smaller projectiles is chosento increase lethality against submunition payloads.
 4. The kineticenergy rod warhead of claim 2 in which the number of larger projectilesis chosen to increase lethality against bomblet payloads.
 5. The kineticenergy rod warhead of claim 2 in which the number of smaller projectilesis chosen to increase the spray pattern density of the projectiles. 6.The kinetic energy rod warhead of claim 3 in which the number of largerprojectiles is chosen to decrease the spray pattern density of theprojectiles.
 7. The kinetic energy rod warhead of claim 2 in which thesmaller projectiles are located proximate an outer region of the coreand the larger projectiles are located proximate the center region ofthe core.
 8. The kinetic energy rod warhead of claim 2 in which theplurality of different size projectiles includes about seventy percentsmaller projectiles and about thirty percent larger projectiles.
 9. Thekinetic energy rod warhead of claim 2 in which the mass of each largeprojectile is greater than the mass of each of small projectile.
 10. Thekinetic energy rod warhead of claim 2 in which all the projectiles havea cruciform cross section.
 11. The kinetic energy rod warhead of claim10 in which the large and small projectiles are tightly packed in thecore with minimal air spacing therebetween.
 12. The kinetic energy rodwarhead of claim 1 in which the all the projectiles are made oftungsten.
 13. The kinetic energy rod warhead of claim 10 in which eachof the small projectiles weigh less than about 50 grams.
 14. The kineticenergy rod warhead of claim 13 in which each of the small projectilesweigh approximately 28 grams.
 15. The kinetic energy rod warhead ofclaim 1 in which the projectiles have a hexagon shape.
 16. The kineticenergy rod warhead of claim 1 in which the projectiles have acylindrical cross section.
 17. The kinetic energy rod warhead of claim 1in which the projectiles have a non-cylindrical cross section.
 18. Thekinetic energy rod warhead of claim 1 in which the projectiles have astar shape cross section.
 19. The kinetic energy rod warhead of claim 1in which the projectiles have flat ends.
 20. The kinetic energy rodwarhead of claim 1 in which the projectiles have a non-flat nose. 21.The kinetic energy rod warhead of claim 1 in which the projectiles havea pointed nose.
 22. The kinetic energy rod warhead of claim 1 in whichthe projectiles have a wedge-shape.
 23. The kinetic energy rod warheadof claim 1 in which the projectiles are cube shaped.
 24. The kineticenergy rod warhead of claim 1 in which the projectiles have athree-dimensional tetris shape.
 25. A kinetic energy rod warheadcomprising: a projectile core including a large number of smallerprojectiles and a small number of larger projectiles; an explosivecharge about the core; and at least one detonator for the explosivecharge.
 26. A kinetic energy rod warhead comprising: a projectile coreincluding a large number of smaller projectiles for increasing thelethality against submunition payloads and a small number of largerprojectiles for increasing lethality against bomblet payloads; anexplosive charge about the core; and at least one detonator for theexplosive charge.